It is not yet next season, and you have started predicted the winner when you don't know how Liverpool's form will be next season because Liverpool have started signing or selling players, despite other teams that also qualify for the next Europa League. If we are to judge based on their previous form, I don't think Liverpool will not qualify for the Champions League for next season because their last upper season was really good because Liverpool was in crazy form despite not winning the Premier League. So just know that any team can win the Europa League, but should depend on their next season form.
Currently, Liverpool is in form, and they may be the best team in form among those teams that qualify for the Europa League next season, but we can't yet concluded that they are the best team because the competition have not yet started. Just remember that if a team does not do well in the groupstages of the Champions League, they will come and play in the Europa League. Even if Sevilla participates in the Europa League next season, there is no guarantee that they will win, despite being the current Europa League champion.